1. Field of the Invention
The present invention relates to a touch apparatus, and more particularly, to an optical touch apparatus capable of effectively preventing the cross talk effect caused by the high arrangement density of the light sensors via the noise suppressing module and operating method thereof.
2. Description of the Prior Art
Recently, with the developing of image display related technology, there are various new types of display apparatus shown on the market to replace the conventional CRT monitor gradually. Wherein, the touch liquid crystal display has advantages such as power saving, smaller size, and inputting by touching directly, therefore, the touch liquid crystal display is popular to the ordinary consumers and becomes the main stream of the display market. The touch liquid crystal display is widely used in various types of electronic products, for example, an Automated Teller Machine (ATM), a point-of-sale (POS) terminal, a visitor navigation system, or an industrial controlling system.
In general, the current touch apparatus, such as a resistance touch apparatus, a capacitance touch apparatus, and an optical touch apparatus, can detect one touch point or more touch points through different detection theorems or ways. In the various types of touch apparatus mentioned above, because the optical touch apparatus has a characteristic of good transmittance; it has become another well-used technology different from the resistance touch apparatus and the capacitance touch apparatus.
Please refer to FIG. 1. FIG. 1 shows a scheme diagram of the conventional optical touch apparatus. As shown in FIG. 1, the conventional optical touch apparatus 1 includes light emitters 10a˜10d, light sensors 12a˜12d and a panel 14, wherein the light emitters 10a˜10d and the light sensors 12a˜12d are set at two different sides on the panel 14, and the light sensors 12a˜12d correspond to the light emitters 10a˜10d respectively.
However, as shown in FIG. 1, a beam emitted from the light emitter 10c includes a plurality of sensing rays. The sensing rays L1˜L3 shown in FIG. 1 are three of the plurality of sensing rays. Once the light sensors 12a˜12d or the light emitters 10a˜10d are arranged very closely, it is possible that some outer large-angled sensing rays (e.g., L1 and L3 shown in FIG. 1) among the plurality of sensing rays are received by the light sensors 12d and 12b near the light sensor 12c respectively instead of being received by the light sensor 12c corresponding to the light emitter 10c. In this way, the light cross talk effect will be generated, and the accuracy of the conventional optical touch apparatus 1 to determine the touch point position will be seriously affected.
Therefore, the invention provides an optical touch apparatus and operating method thereof to solve the aforementioned problems.